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United States Patent |
6,017,197
|
Jensen
,   et al.
|
January 25, 2000
|
Suction sound damper for a refrigerant compressor
Abstract
A suction sound damper for a refrigerant compressor is disclosed, having an
inlet, which is arranged to be connected to a suction port, and an outlet,
which is arranged to be connected to the refrigerant compressor, and also
having at least one damping volume. It is desirable for a suction sound
damper of that kind to be of simple and inexpensive construction, and to
contribute to increasing the efficiency of a refrigerant compressor. For
that purpose, it is formed from a first and second half which define an
internal space in which the damping volume is arranged, the first half
having projecting into the internal space a gas deflection wall which, at
least over sections thereof, forms a lateral limitation of a flow path
free from throttle points between inlet and outlet.
Inventors:
|
Jensen; Michael Skovgaard (Silkeborg, DK);
Iversen; Frank Holm (Padborg, DK)
|
Assignee:
|
Danfoss Compressors GmbH (Flensburg, DE)
|
Appl. No.:
|
981277 |
Filed:
|
December 23, 1997 |
PCT Filed:
|
June 21, 1996
|
PCT NO:
|
PCT/DK96/00272
|
371 Date:
|
December 23, 1997
|
102(e) Date:
|
December 23, 1997
|
PCT PUB.NO.:
|
WO97/01036 |
PCT PUB. Date:
|
January 9, 1997 |
Foreign Application Priority Data
| Jun 23, 1995[DE] | 195 22 383 |
Current U.S. Class: |
417/312; 181/249 |
Intern'l Class: |
F04B 053/00 |
Field of Search: |
417/312
181/403,272,249,250
|
References Cited
U.S. Patent Documents
4109751 | Aug., 1978 | Kabele | 181/247.
|
4313715 | Feb., 1982 | Richardson, Jr. | 417/312.
|
4370104 | Jan., 1983 | Nelson et al. | 417/312.
|
4755108 | Jul., 1988 | Todescat et al. | 417/312.
|
4960368 | Oct., 1990 | Lilie | 417/312.
|
5201640 | Apr., 1993 | Heinzelmann et al. | 417/312.
|
Primary Examiner: Freay; Charles G.
Assistant Examiner: Evora; Robert Z.
Attorney, Agent or Firm: Lee, Mann, Smith, McWilliam, Sweeney & Ohlson
Claims
We claim:
1. Suction sound damper for a refrigerant compressor, the sound damper
having an inlet which is arranged to be connected to a suction port and an
outlet which is arranged to be connected to the refrigerant compressor,
and also having at least one damping volume, the sound damper being formed
from a first and a second half which define an internal space in which the
damping volume is arranged, the first half having a gas deflection wall
projecting from the first half into the internal space which, at least
over sections of the gas deflection wall, forms a lateral limitation of a
flow path free from throttle points between the inlet and the outlet.
2. Suction sound damper according to claim 1, in which the inlet opens
substantially parallel to the gas deflection wall in the internal space.
3. Suction sound damper according to claim 1, in which the outlet extends
substantially parallel to the gas deflection wall.
4. Suction sound damper according to claim 1, in which the gas deflection
wall has a curve effecting a directional change between the inlet and the
outlet.
5. Suction sound damper according to claim 4, in which the gas deflection
wall is of increased height proximate the curve.
6. Suction sound damper according to claim 1, in which a boundary wall is
provided substantially parallel to the gas deflection wall and extending
from an opposite side of the inlet and the outlet.
7. Suction sound damper according to claim 6, in which the boundary wall is
located on the first half.
8. Suction sound damper according to claim 1, in which the boundary wall
has a predetermined spacing from a top wall of the second half.
9. Suction sound damper according to claim 1, in which the gas deflection
wall extends, at least for a majority of its length, spaced apart from an
outer wall of the first half.
10. Suction sound damper according to claim 1, in which the gas deflection
wall has a predetermined spacing from a top wall of the second half.
11. Suction sound damper according to claim 1, in which the inlet opens
into the internal space close to a base of the first half.
12. Suction sound damper according to claim 1, in which the outlet includes
an outlet connector which is fixed between the first and the second half,
an opening of the outlet connector being located in the internal space.
13. Suction sound damper for a refrigerant compressor, the sound damper
having an inlet which is arranged to be connected to a suction port and an
outlet which is arranged to be connected to the refrigerant compressor,
and also having at least one damping volume, the sound damper being formed
from a first and a second half which define an internal space in which the
damping volume is arranged, the first half having a gas deflection wall
projecting into the internal space which, at least over sections of the
gas deflection wall, forms a lateral limitation of a flow path free from
throttle points between the inlet and the outlet, and which has a
predetermined spacing from a top wall of the second half.
14. Suction sound damper according to claim 13, in which the inlet opens
substantially parallel to the gas deflection wall in the internal space.
15. Suction sound damper according to claim 14, in which the gas deflection
wall is of increased height proximate the curve.
16. Suction sound damper according to claim 13, in which the outlet extends
substantially parallel to the gas deflection wall.
17. Suction sound damper according to claim 13, in which the gas deflection
wall has a curve effecting a directional change between the inlet and the
outlet.
18. Suction sound damper according to claim 13, in which a boundary wall is
provided substantially parallel to the gas deflection wall and extending
from an opposite side of the inlet and the outlet.
19. Suction sound damper according to claim 18, in which the boundary wall
has a predetermined spacing from a top wall of the second half.
20. Suction sound damper according to claim 13, in which the gas deflection
wall extends, at least for a majority of its length, spaced apart from an
outer wall of the first half.
Description
BACKGROUND OF THE INVENTION
The invention relates to a suction sound damper for a refrigerant
compressor, having an inlet, which is arranged to be connected to a
suction port, and an outlet, which is arranged to be connected to the
refrigerant compressor, and also having at least one damping volume.
Such a suction sound damper is known from U.S. Pat. No. 5,201,640. In this
suction sound damper, the inlet is connected to the outlet by way of a
tube. The tube forces a number of direction changes on the gaseous
refrigerant flowing through it. The tube has a number of radial openings
through which the inside of the tube is in connection with the damping
volume which surrounds the tube. The known solution is firstly relatively
expensive, because the tube is constructed as a separate component which
accordingly requires a further manufacturing step and additional material.
Moreover, the many directional changes in the flow of refrigerant lead to
an increased flow resistance, with the result that the efficiency of a
compressor which is provided with such a suction sound damper may suffer.
Another suction sound damper is known from DE 36 45 083 C2. This suction
sound damper consists of two halves that are joined together and then
enclose four chambers which are connected to one another partly by
throttling points and partly by a throttling channel. These throttling
points and channels also lead to a relatively large flow resistance, with
adverse consequences for the efficiency of a compressor equipped
therewith. Such a suction sound damper can, however, be manufactured
relatively inexpensively.
SUMMARY OF THE INVENTION
The invention is based on the problem of providing a simple and inexpensive
suction sound damper for a refrigerant compressor, which allows improved
efficiency of the refrigerant compressor.
That problem is solved in a suction sound damper of the kind mentioned in
the introduction in that it is formed from a first and a second half which
define an internal space in which the damping volume is arranged, the
first half having projecting into the internal space a gas deflection wall
which, at least over sections thereof, forms a lateral limitation of a
flow path free from throttle points between inlet and outlet.
With such a construction the flow resistance of the suction sound damper
can be reduced quite considerably. The efficiency of the compressor which
is provided with such a suction sound damper can therefore be increased.
Surprisingly, there is a satisfactory sound damping even without
relatively large throttling resistances. On the contrary, it is now
possible for the refrigerant flowing through the flow path to expand into
the damping volume arranged likewise in the internal space. The function
of the gas deflection wall is substantially merely to guide the gaseous
refrigerant, which flows through the suction sound damper, at least over
sections thereof from the inlet to the outlet. The gas deflection wall
itself no longer forms any throttling points. Because the flow losses are
kept small, the refrigerant can flow through the suction sound damper at a
uniform speed, but with a lower pressure drop. Because the suction sound
damper is arranged, in the case of encapsulated domestic refrigeration
machines, generally within the capsule, that is, within an atmosphere of
refrigerant that has already been heated, the flow speed that can be
achieved has the advantage that the refrigerant that is still cold in the
suction sound damper does not become appreciably warm. Any such warming
leads to loss of density and thus to impairment of the efficiency of the
refrigerant compressor.
The inlet preferably opens substantially parallel to the gas deflection
wall into the internal space. The gas deflection wall is thus located
approximately tangentially to the incoming refrigerant. Eddying of the
refrigerant, which could lead to an increase in the flow resistance and to
slowing of the refrigerant, are therefore largely avoided.
It is also preferred for the outlet to run substantially parallel to the
gas deflection wall. Eddying is also avoided by this measure. Flow
resistances which could occur at the transition between the flow path and
the outlet are thus kept as small as possible.
The gas deflection wall preferably has a curve effecting a directional
change between inlet and outlet. This has the advantage, firstly, that
such a suction sound damper can be used also with known refrigerant
compressors, in which inlet and outlet of the suction sound damper are not
in alignment but are offset by, for example, 90.degree. with respect to
one another. The curve of the gas deflection wall also has the advantage,
however, that the incoming refrigerant is pressed against the gas
deflection wall, whereby reliable guidance of the refrigerant along the
flow path is ensured. The curve should in that case be as "round" or
"gentle" as possible in order to effect a gradual directional change in
the refrigerant flow. The larger is the radius of curvature of the curve,
the smaller are the flow losses. The radius of curvature is limited, of
course, by the overall size of the suction sound damper.
The gas deflection wall is preferably of increased height in the region of
the curve. By this means the refrigerant flowing is prevented from being
displaced or "sloshed" over the gas deflection wall because of centrifugal
force, so that it is kept, mainly at least, on the flow path.
In an especially preferred construction, a boundary wall is provided
substantially parallel to the gas deflection wall on the opposite side of
inlet and outlet. Inlet and outlet thus open out between the gas
deflection wall and the boundary wall. In this manner, slowly rotating
turbulence is prevented from forming on the side of the flow path remote
from the gas deflection wall; such turbulence leads to transfer of heat
from the outside of the sound damper to the suction line, thus allowing
the refrigerant inside the suction sound damper to become warm when it
stays there for a relatively long time. As stated above, such warming
would contribute to impairment of the efficiency of the refrigerant
compressor. Projections in the first and second half can form a labyrinth
in the damping volume. In that case, transfer of heat from the outside of
the sound damper to the suction channel is reduced.
The boundary wall also is preferably provided on the first half. This
simplifies manufacture.
In an especially preferred construction, the gas deflection wall runs, at
least for the majority of its length, spaced apart from an outer wall of
the first half. Between the outer wall and the gas deflection wall
quiescent gas volumes are able to form, which contribute to thermal
insulation between the outer wall and the gas deflection wall.
Introduction of heat into the flow channel from this outer wall is
therefore very reliably prevented. Warming of the refrigerant flowing
through the suction sound damper is thus also reduced.
The gas deflection wall and/or the boundary wall preferably have a
predetermined spacing from the top wall of the second half. The flow path
for the refrigerant is therefore combined for virtually the entire
cross-section of the flow channel with a relatively large damping volume
inside the suction sound damper. Pressure pulses that occur as a
consequence of the back and forth movement of the piston of the
refrigerant compressor and therefore in combination with the pulsed
suction of the refrigerant, can then spread out in the damping volume,
without having to overcome relatively large throttling resistances. This
produces a very effective sound damping.
In an especially preferred construction, provision is made for the inlet to
open into the internal space close to the base of the first half. In that
case, the refrigerant is able to bend round at a relatively low pressure
level along the base of the first half against this base and clings, as it
were, to the base of the first half. This effect arises because the
incoming refrigerant gas entrains the stationary gas in the region of the
flow path with it and a reduced pressure consequently occurs along the
wall; the main gas flow delivers the region of reduced pressure towards
the wall.
The outlet is preferably provided with an outlet connector which is fixed
between the first and the second half, an opening of the outlet connector
being located in the internal space. An inflow into the outlet connector
is thereby effected directly from the flow path and not from the
surrounding damping volume. The effective opening cross-section is
enlarged here. The damping volume is therefore able to fill with quiescent
refrigerant in which only a few movements occur. Intermingling of warm and
cold refrigerant takes place only to a very slight extent.
BRIEF DESCRIPTION OF THE DRAWING
The invention is described hereinafter with reference to a preferred
embodiment in conjunction with the drawings, in which:
FIG. 1 is a perspective exploded view of a suction sound damper.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A suction sound damper 1 comprises a first half 2 and a second half 3 which
together define an internal space when they are joined to one another by
their flanges 4, 5.
The suction sound damper 1 has an inlet 6, which can be connected by way of
an inlet connector 7 to a suction port of a housing, not illustrated.
Refrigerant is sucked in through this suction port.
The suction sound damper further has an outlet 8 in which an outlet
connector 9 can be inserted. The outlet connector 9 can be connected to a
refrigerant compressor, likewise not illustrated.
In the first half 2 there is arranged a gas deflection wall 10 which runs
from inlet 6 to outlet 8 and extends in the internal space between the two
halves 2, 3. The gas deflection wall 10 here forms a curve 11 with as
large a radius of curvature as possible.
In the region of the inlet 6 the gas deflection wall 10 is aligned
substantially parallel to the inlet 6. Inflowing refrigerant therefore
flows substantially tangentially to the gas deflection wall 10. The same
applies to the region of the outlet 8, where the gas deflection wall 10 is
arranged substantially parallel to the outlet 8.
The inlet connector 7 has its opening close to the base 12 of the first
half 2. In that case, the so-called "Coanda effect" causes the gaseous
refrigerant to attach itself to the base 12 of the first half 2. A flow
path for the refrigerant therefore develops along the gas deflection wall
10. The refrigerant, as stated, is held against the base by the Coanda
effect, and is held against the gas deflection wall by the centrifugal
force which presses the gaseous refrigerant against the gas deflection
wall 10 on a change in direction.
In the region of the curve 11, the gas deflection wall 10 has an increased
height 13. This increased height 13 can extend approximately as far as the
outlet 8; the increased height 13 may be interrupted by a gap 14. The gap
14 is in that case preferably arranged where there is no concave curvature
of the gas deflection wall 10 and, if possible, where there is a convex
curvature.
Substantially parallel to the gas deflection wall 10 there is arranged a
boundary wall 15. The boundary wall 15 prevents slowly rotating turbulence
from forming on the side of the flow path opposite to the gas deflection
wall 10; although this turbulence does not lead to an appreciable increase
in the flow resistance through the suction sound damper, it could lead to
warming of the gaseous refrigerant staying in the suction sound damper. A
region between the gas deflection wall 10 and the boundary wall 15 can now
be defined as the flow path 16 or gas conduction path. Note, however, that
this flow path 16 would develop in virtually the same manner if the
boundary wall 15 were not present.
The gas deflection wall 10 runs, at least for the majority of its length,
always spaced apart from an outer wall 17 of the first half. Dead spaces
18 which fill with gaseous refrigerant are therefore created. The same
applies to the boundary wall 15, which likewise runs spaced apart from the
outer wall 17 of the first half and encloses with this outer wall 17 a
dead space 19.
The gas deflection wall 10 and the boundary wall 15 terminate at a
predetermined spacing from a top wall 20 of the second half 3. Virtually
the entire space between the top wall 20 and the upper side of the gas
deflection wall 10 where the height is not increased and the upper side of
the boundary wall 15 is therefore available as damping volume. This is
supplemented by the dead spaces 18, 19. In the region of the gas
deflection wall 10 there is also a connection between the flow path 16 and
the damping volume, for example, by way of the gap 14 or the region in
front of the raised wall 13 of the curve 11. The upper side of the gas
deflection wall 10 here follows the top wall 20 with a constant gap. In
this manner a very good connection between the flow path and the damping
volume is created. Short pressure surges, which are caused by the pulsed
feeding of the refrigerant, are then able to expand in this damping
volume; the expansion does not encounter any appreciable flow resistance.
On the other hand, movement of gas in the damping volume is only very
limited, so that there is virtually no, or only negligible, exchange of
the refrigerant gas from the flow path 16 with gas from the damping
volume.
The outlet connector 9 is simply inserted between the first and the second
halves 2, 3. It can be made of a material having a different thermal
conductivity from the material of the two halves 2, 3.
The outlet connector 9 has an inlet opening 21 which is located in the
internal space enclosed by the two halves 2, 3, to be precise, in the
region of the flow path 16. Inflow into the outlet connector 9 is
therefore effected only from the region of the gas deflection wall 10, and
not from the surrounding damping volume. Because there is virtually no
radial flow into the connector from the damping volume, a greater
effective cross-section is achieved in the outlet connector 9.
Whereas in the region of the boundary wall 15 there is a gap between the
top wall 20 and the boundary wall 15 for the entire length of the boundary
wall 15, the gas deflection wall 10 may possibly, in the region where its
height is increased, abut the top wall 20. This greater height 13 not only
prevents gas being displaced over the gas deflection wall; it may also
intercept oil droplets entrained with the refrigerant and also drops of
refrigerant that has already condensed. These drops can then run down the
gas deflection wall 10 and, if it is so desired, drain off through the
inlet 6 when the compressor next stops. This is easily possible because
the inlet, as stated above, is arranged close to the base 12. Ingress of
drops of fluid into the compressor is largely avoided.
By means of the suction sound damper 1, not only is a reduction in the flow
resistance achieved, with the result that the compressor requires less
effort to draw in the refrigerant; the refrigerant is also able to flow
more quickly through the suction sound damper 1, with the result that the
risk that the refrigerant will become warm is reduced. Efficiency is also
improved as a result of this measure.
Both halves 2, 3 can be manufactured from plastics material as
injection-moulded parts. With such a construction both the gas deflection
wall 10 and the boundary wall 15 can be integrally moulded directly with
the first half 2, without further measures being necessary. The profiled
connections between the two halves 2, 3, which later result in an improved
sealing of the suction sound damper, can be similarly moulded.
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